Razor Pages - Foreach 循环遍历列表以获取要在 Razor 视图上显示的数据
Razor Pages - Foreach loop through list to get data to display on razor view
我无法在剃刀视图上显示数据。我目前正在获取数据并在 DataAccessLayer.GetData() 函数中填充我的对象。我的对象列表被填充并存储。但是,我的对象列表计数在剃刀视图中为 0,因此它什么也不显示。我是否 "newing" 在视图中正确地设置了我的对象?这是第一次使用剃须刀页面模板,因此它是一个学习曲线。
剃刀页面:
<form method="post" asp-page-handler="GetData">
<input id="txtSearch" name="search" />
<button class="btn btn-lg btn-dark" id="btnSubmit" name="Submit" />
</form>
@{ List<ObjectsModel> objects = new List<ObjectsModel>();
@foreach (var record in objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}
PageModel:
public class ObjectsModel : PageModel
{
public string COLUMN1 { get; set; }
public string COLUMN2 { get; set; }
public string COLUMN3 { get; set; }
public void OnGet()
{
}
public void OnPostGetData(string search)
{
List<ObjectsModel> objects = new List<ObjectsModel>();
DataAccessLayer.GetData(search, out objects);
return;
}
}
数据访问层:
public class DataAccessLayer
{
public static bool GetData(string ID, out List<ObjectsModel> objects)
{
string connectionString = "";
objects = new List<ObjectsModel>();
try
{
SqlConnection connection = new SqlConnection(connectionString);
connection.Open();
SqlCommand command = connection.CreateCommand();
command.CommandType = System.Data.CommandType.Text;
command.CommandText = @"SELECT top 50 COLUMN1, COLUMN2, COLUMN3
"FROM Table";
SqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
ObjectsModel item = new ObjectsModel();
item.COLUMN1 = reader.GetValue(0).ToString().Trim();
item.COLUMN2 = reader.GetValue(1).ToString().Trim();
item.COLUMN3 = reader.GetValue(2).ToString().Trim();
objects.Add(item);
}
reader.Close();
reader = null;
command = null;
connection.Close();
connection = null;
return true;
}
catch (Exception exc)
{
exc.ToString();
return false;
}
}
}
更改这段代码
@{ List<ObjectsModel> objects = new List<ObjectsModel>();
@foreach (var record in objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}
至此
public class ObjectsModel : PageModel
{
public string COLUMN1 { get; set; }
public string COLUMN2 { get; set; }
public string COLUMN3 { get; set; }
public List<ObjectsModel> objects{get; set;}
public void OnGet()
{
}
public void OnPostGetData(string search)
{
DataAccessLayer.GetData(search, out objects);
return;
}
}
@{
@foreach (var record in Model.objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}
我通过将我的对象列表 属性 添加到我的对象模型并在那里而不是在视图页面上对其进行初始化来使其工作。我不再需要 Razor 视图中的引用,因为我可以使用 @Model.objects 访问循环中的列表。显然我已经更改了我的页面模型和属性的名称,因为这最终将成为生产中的实时项目。
已更新页面模型:
public class ObjectsModel : PageModel
{
public class Object
{
public string COLUMN1 { get; set; }
public string COLUMN2 { get; set; }
public string COLUMN3 { get; set; }
public List<ObjectsModel> objects = new <ObjectsModel>();
}
public void OnGet()
{
}
public void OnPostGetData(string search)
{
DataAccessLayer.GetData(search, out objects);
return;
}
}
更新的剃刀页面:
@{
@foreach (var record in @Model.objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}
我无法在剃刀视图上显示数据。我目前正在获取数据并在 DataAccessLayer.GetData() 函数中填充我的对象。我的对象列表被填充并存储。但是,我的对象列表计数在剃刀视图中为 0,因此它什么也不显示。我是否 "newing" 在视图中正确地设置了我的对象?这是第一次使用剃须刀页面模板,因此它是一个学习曲线。
剃刀页面:
<form method="post" asp-page-handler="GetData">
<input id="txtSearch" name="search" />
<button class="btn btn-lg btn-dark" id="btnSubmit" name="Submit" />
</form>
@{ List<ObjectsModel> objects = new List<ObjectsModel>();
@foreach (var record in objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}
PageModel:
public class ObjectsModel : PageModel
{
public string COLUMN1 { get; set; }
public string COLUMN2 { get; set; }
public string COLUMN3 { get; set; }
public void OnGet()
{
}
public void OnPostGetData(string search)
{
List<ObjectsModel> objects = new List<ObjectsModel>();
DataAccessLayer.GetData(search, out objects);
return;
}
}
数据访问层:
public class DataAccessLayer
{
public static bool GetData(string ID, out List<ObjectsModel> objects)
{
string connectionString = "";
objects = new List<ObjectsModel>();
try
{
SqlConnection connection = new SqlConnection(connectionString);
connection.Open();
SqlCommand command = connection.CreateCommand();
command.CommandType = System.Data.CommandType.Text;
command.CommandText = @"SELECT top 50 COLUMN1, COLUMN2, COLUMN3
"FROM Table";
SqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
ObjectsModel item = new ObjectsModel();
item.COLUMN1 = reader.GetValue(0).ToString().Trim();
item.COLUMN2 = reader.GetValue(1).ToString().Trim();
item.COLUMN3 = reader.GetValue(2).ToString().Trim();
objects.Add(item);
}
reader.Close();
reader = null;
command = null;
connection.Close();
connection = null;
return true;
}
catch (Exception exc)
{
exc.ToString();
return false;
}
}
}
更改这段代码
@{ List<ObjectsModel> objects = new List<ObjectsModel>();
@foreach (var record in objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}
至此
public class ObjectsModel : PageModel
{
public string COLUMN1 { get; set; }
public string COLUMN2 { get; set; }
public string COLUMN3 { get; set; }
public List<ObjectsModel> objects{get; set;}
public void OnGet()
{
}
public void OnPostGetData(string search)
{
DataAccessLayer.GetData(search, out objects);
return;
}
}
@{
@foreach (var record in Model.objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}
我通过将我的对象列表 属性 添加到我的对象模型并在那里而不是在视图页面上对其进行初始化来使其工作。我不再需要 Razor 视图中的引用,因为我可以使用 @Model.objects 访问循环中的列表。显然我已经更改了我的页面模型和属性的名称,因为这最终将成为生产中的实时项目。
已更新页面模型:
public class ObjectsModel : PageModel
{
public class Object
{
public string COLUMN1 { get; set; }
public string COLUMN2 { get; set; }
public string COLUMN3 { get; set; }
public List<ObjectsModel> objects = new <ObjectsModel>();
}
public void OnGet()
{
}
public void OnPostGetData(string search)
{
DataAccessLayer.GetData(search, out objects);
return;
}
}
更新的剃刀页面:
@{
@foreach (var record in @Model.objects)
{
<tr>
<td>
@Html.DisplayFor(modelItem => record.COLUMN1)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN2)
</td>
<td>
@Html.DisplayFor(modelItem => record.COLUMN3)
</td>
</tr>
}
}